You can take flight to Qingdao, Yantai and Weihai, then take train or long distance bus to Yishui county to take our trip.
Qingdao - Yishui, train or bus, about 3 hours.

Day01, Arrive Yishui train station or bus station,  pick you up at Yishui Train Station or bus station,  and drive about 0.5 hour to Yishui Glowworm Glow Worm Karst Cave (Yishui Underground Fluorescent Lake ) for visiting karst scenery, and take boat riding about 1200 meters  to watch one of the lighting or fire insects, firelies glow worm, and this firefly just living in the dark cave. Thousands of lighting flashing glowworms on roof like countless stars twinkling in the welkin. The glowworms on the top of the head as if a magnificent incomparable diamond necklace and the fickle sky in four seasons, the drop you off at Yishui Long Distance bus back to Qingdao. .(L).
Quotation: 125USD/p.p.
Minimum 2 persons in your party.

Included: local style meals marked,  entrance fee for sightseeing, boat ticket in the cave, transfers and transportation by private car as marked,  local private English speaking guide service,  bus or train ticket from Yishui to Qingdao, tour body insurance.
Excluded: train or bus tickets from Qingdao to Yishui, any other service not included above.

Better time to watch fireflies: all year around.